This invention relates to a tire building apparatus having a forming drum, bead setters and bead supply means.
A tire building apparatus hitherto used has been known, for example, disclosed in Japanese Patent Application Laid-open No. 57-32,935. This apparatus comprises a tire forming drum rotatably supported at one end and having an outer circumference about which a tire constituting member is wound. The apparatus further comprises bead setters movable toward and away from the forming drum for holding beads and setting them in position on the tire constituting member, and bead supply means for supplying the beads to the bead setters. The bead supply means is arranged remote from the forming drum and the bead setters. The apparatus further comprises a base movable across passages of the bead setters, a pair of front plates fixed to the base, and a plurality of bead chucks circumferentially spaced and supported by the front plates and movable in radial directions in synchronism with each other to grasp the beads on their inside.
With such a tire building apparatus, however, as the bead supply means is independently located remote from the tire forming drum, the beads grasped by the bead supply means and hence the beads held by the bead setters are shifted from or misaligned with the forming drum because accumulation of manufacturing errors, positioning errors and deformations of the forming drum. In case that they are misaligned to an excessive extent, in fitting beads on the outside of the forming drum to set the beads in position on the tire constituting member, the beads are likely to contact the tire constituting member to damage it to an extent that it can seldom be repaired.